Friction drive-chain.



PATENTBD SEPT. 1,'-19oa. w. J. BELcEEE & w. M. BUTLER. PRIGTION DRIVE 0mm.

APPLIOATIOI FILED I4! 25, 1908.

. and then appl (strips of some frictional ina- UNITED STATES PATENT OFFICE.

WARREN J. BELCI-IER AND WIL AM M. BUTLER, or HARTFORD, CONNECTICUT, ASSIGNORS PORATION.

TO: THE WHITNEY MANUFACTURING COMPANY, OF HARTFORD, CONNECTICUT, A COR- FRICTIOK DRIVE-CHAIN.

Specification of Letters Patent.

Patented Sept. 1, 1908.

Application filed May 25, 1908. Serial No. 434,917.

To a'll'whom it may concern: I

Be it known that we, WARREN J. BELCHER and WILLIAM M. BUTLER, citizens of the United States of America, residing at Hartford, in the county of Hartford and State of Connecticut, have invented new and useful Improvements in Friction Drive-Chains, of which the following is a specification.

This invention relates to friction drivechains, the object of the invention being to improve the construction thereof in so far as itjelates to the application to the links of a chain of a'covering of some suitable material, as leather, to serveas an inclosing casing for said links, said m'aterial coniing in frictional contact. with the sides of a grooved pulley,

and constitutingthe actual driving elelnent.

(or the latter. Thedriving pulley-for these inextensible'drive-belts of the type referred to herein has a V-sha ed groove, and to provide a drive-belt which in cross section, shall have beveled sides corres onding to the sides of the groovein' the ulliiy, it has generally been the practice. to )evel the plates which constitute one of the elements of a chain,

terial as leat er, to these plates, thefrictional material being f form thickness. 80

'The object of this irivention is to provide a eonstructionwhereby the bcvcling of the sides-of the drive-'chainds obtained by so (ashioni the strips,of the frictional material that t at portion' thereof disposed on the two-opposite-sides of therbelt will be so tared in cross sectional form as to properly E: the V-groove in the pulley whereby the elements; of the belt or' chamwhich consti-- ."fl-tut e-the inextensible core of the structure flmay be made 'with parallel sides, which greatly facilitates an oheapens the constructlo'n of'said chain. 4

A great advantage of a drive-chain constructed as herein set-forth lies in the fact that it pro. 'des means to ieldingly cushion the sides t ereof, whereb while it permits the chain to be drawn tightly into the groove in the pulley, italso permits it to leave the grooveeasily at the point where the chain runs out of it, owin -to the fact that each 'fpiec'e of the frictiona material, as disposed on either side of'the chain, constitutes a yield- Wedge, the thickness of which increases j from the bottom upward. Therefore as the 56 strain on the increases and it is drawnof substantially uni "in this instance being tion in Figs. 3

deeper into the grooved pulley the constantly increasing thickness of the cushioning covering material prevents the cham from wedging in the groove of the pulley owing to the fact that the upper portion thereof is compressible to a greater degree than the lowerportion, and the effect of this is to make it much easier for the chain to leave the groove in the pulley where it runs ofithe latter; whereas, if the chain elements inclosed by the covering. material were arallel with the sides of the groove, and sai material of uniform thickness, each chain link or element wouldeonstitute a hard unyielding'wedge which, under heavy strains, would have a tendency to stickin the groove of the pulley.

The invention is fully illustrated in the accompanying drawings, in which Figure 1 1s a perspective view of two blocks and a connecting-link of a chain, the covering of frictional material beingbroken away and showing the fastenim device forthe naterial on the under side o thelink. Fig. 2is' a similar view to Fig. 1 but showing the fas toning device for the covering of frictional material located on the upper. side of the chain. Figs. 3 and 4 are side elevations of the pieces of frictional material which en- "elop each alternate elemcnt'of the chain showing the cross sectional disposition of the material to provide the tapered side pieces thereol,Fig. 3- showing the cross sectional. form of the piece when the latter is secured on the under side, and Fig. 4 showing its shape when it is secured on the upper side thereof. Fig. '5 is a sectional elevation of the completed ehainshowing the fastening device on the underside, and Fig. 6 is a sinnlar view showing the chain in its relation to the grooved pulley, the frictional material fastened on the upper side of the chain.

Referring now to these drawin s,The

chain is made up of alternate blocks a and side plates or links '6, the. latter being riveted to the blocks in the usual manner. The side lates, as shown in Figs. 5 and 6, are arallel. The side plates, in the construction s own in Figs. 1 and 5, are provided on the lower edge thereof with-teeth or projections c integral with said plates which are adapted to ex-' tend through the opposite abutting edges of a piece of flexible, frictional material'd, two of which stripsflare shown in end elevaiooj , and as'ftheydifler some- 419- of the channel It.

what in cross sectional form, this difference will be referred to and explained further on. These strips, as shown in Figs. 5 and 6, particularly are adapted to encircle the chain inclosing the two oppositely located side .lates I, as shown in the drawing, and overapping a portion of the ends of the blocks a which extend between the side plates.

The mode of fastening the frictional ma terial to the side plates forms no part of the present invention but the n'ianncr of securing the abutting ends of said material ,shown herein is one particularly adapted to secure'said material to'said side plates in a manner which will prevent the movement thereof relative to the chain, when in use.

As shown herein, the teeth or projections c which are, shown. as extending from the lower borders of. the side plates Hi the construction shown In Figs. 1 and 5, and from the opposite borders of the side plates in the construction shown in Figs. 2 and (5, extend through metal plates 6 having down-turned serrated borders f which are forced into the frictional material in lines paralleling the abutting edges thereof,-the teeth 0 being bent over against the outside of the plate and clenched thereagainst.

As hereinbefore stated, the primary object of the present invention is to provide a chain of the character lescrilieil, the tapering sides which bear in the grooved pulley being provided entirely by the wedge-shaped cross sectional-form of the frictional material (Z, said material being cut into strips having sub-- stantially a width equal to thelengt'h of each alternate element of the chain which they are adapted to inc-lose... In making the strips shown in Fig. 3, a strip of friction material, as leather, (whose maximum thickness is at least equal to the thickness at g of the piece shown in said figure) may be run through a machine which will cut a channel It therein centrally of the strip, and from. each. border of said channel taper the sides thereof to a mint near the ends or edges of the strip, as at these ends being left of substantially the same thickness as the'inaterialat the bottom When this strip is applied to the chain, the covering material will as- 'suine the cross SOC-l/lUHftl form shown in Fig.

5, that is to say, the cross sectional tapering form of the chain \\lll liedue entirely .to the cross sectional form of the strip of frictional material which incloscs it, the purpose and function of which construction has been pre viously pointed out herein.

In the construction shown in Figs. 2, 4, and (3, the sole change consists in so forming the covering strip (1 in cross section as to permit the abutting edges thereof to be secured together on the upper side of the side plates or links, instead of the under side asshown in ,l igs. 1' and 5; and, obviously, this requires that the taper of the sides of the covering stri or piece shall be reversed as compared with Fig. 3, otherwise, the construct ion is the same save for the rib m which, if desired may be provided centrally between the two ends and which, when the stri is in position on the link, will extend up between the lower edges of the latter thereby serving more or less to hold. the covering material more securely in position.

What we claim, is

1. A friction-drive chain comprising pivotally connected elements, a flexible covering strip extending transversely around each alternate element, that part of said strip 1ying next the sides of the chain being wedgeshaped in cross section, and a fastening device to engage the abutting ends of each strip to tightly secure the covering strip to the inclosed chain element.

2. A friction-drive chain comprising pivotally eonnected blocks and side-plates, a covering strip extending transversely around. each set of side-plates, that part of said strip lying next the sides of the chain being wedgeshaped in cross section, and a fastening de- Vice to engage the abutting ends of each strip, one edge of the side plates constituting a part of said fastenilig'device.

3. A friction-drive chain comprising pivotally connected elements, a covering strip extending transversely around each alternate element, said strip tapering in cross sectional form from the inner towards the outer edge of the chain, and means to secure said strip in fixed position on the chain element it incloscs.

' WARREN J. BELCl-IER.

WLLLIAM M. BUTLER. \V'tnesses:

.J as. \V. GREEN,

(lnonon l1. .Mansn. 

